1. Technical Field
The disclosure relates to a method of manufacturing an element chip from a substrate held by a holding sheet.
2. Description of the Related Art
As a method of dicing a substrate which includes a plurality of element regions demarcated by an isolation region, plasma dicing in which the isolation region is subjected to plasma etching so as to divide the substrate into a plurality of element chips is known. Recently, an electronic device has a reduced size and a reduced thickness, and thus the thickness of an IC chip and the like mounted in the electronic device is reduced. With this trend, the thickness of a substrate for forming an IC chip and the like as a target of plasma dicing is also reduced, and thus the substrate is easily bent.
Patent Literature 1 discloses that a substrate in a state of being held in a transporting carrier which includes a frame and a holding sheet for covering an opening portion of the frame is placed on a stage included in a plasma treatment apparatus and plasma dicing is performed, in order to improve handling characteristics of the substrate or an element chip during transporting or picking-up. In a case using a holding sheet, if the temperature of the holding sheet becomes high, the holding sheet is, for example, stretched or damages. Thus, a divided element chip is fallen or picking an element chip up from the holding sheet is difficult. Thus, the stage includes an electrostatic suction mechanism for sticking a holding sheet and the state is cooled. A holding sheet is electrostatically sucked to the cooled stage, and thus the holding sheet in the process of plasma treatment is also cooled.